打印1到N的最大数

#include <iostream>using namespace std;void printChar(char *str){    int i=0;    while(str[i]=='0')        ++i;    cout<<str+i<<endl;      }void printNum(char* str,int n,int index){    if(n==index)    {        printChar(str);        return ;    }           for(int i=0;i<10;++i)    {        str[index] = i+'0';        printNum(str,n,index+1);    }}int main(){    int n;    while(cin>>n)    {        char *str = new char[n+1];        memset(str,'0',n);        str[n] = '\0';        printNum(str,n,0);    }    return 0;}